Windback device



Dec. 7, 1943. L, L HARMQN 2,336,245

WINDBACK DEVICE Filed Aug. 4, 1940 Patented Dec. 7, 1943 UNITED STATES PATENT OFFICE WINDBACK DEVICE Lacey L. Harmon, St. Paul, Minn., assignor to John A. Stees, II, St. Paul, Minn.

Claims.

My invention relates to an improvement in windback devices wherein it is desired to provide a device for use on motion picture apparatus for winding the film back upon the supply roll to produce certain photographic efiects.

It is sometimes desired to provide a means of winding the film back upon the supply roll after exposure or partial exposure thereof in order to make lap dissolves, superimposed pictures, action titles, and other unusual effects. A lap dissolve is made by fading out one scene by means of a fading device or by other suitable means, winding back the film to the start of the fade out, and fading in the next scene. By this means the scene is gradually made to fade from one scene to another without any definite break between the scenes. Superimposed pictures may be made either by making a double exposure of a section of film, or by masking a portion of the film in its travel past the lens, and then rewinding the film and leaving the previously masked film portion unmasked while masking the previously exposed portion thereof. Action titles may be made by taking an action picture, winding the film back,

and taking a picture of a title, this title thus being superimposed upon the action picture. All of these special effects as well as other unusual efiects, require that the film be wound partially back upon the supply roll so that it may again be exposed.

Most motion picture cameras in common use include a film moving mechanism which is not reversible in action. In other words the film is drawn in one direction by the film moving mechanism. An attempt to wind the film in the opposite 9 direction results in the tearing of the film by the film moving mechanism during the reverse movement thereof. This is particularly true of the common pull-down type of film moving mechanism, which is usually equipped with a pull-down claw which is not reversible in action.

It is the object of the present invention to provide a windback mechanism which may either be manufactured as a part of the original camera, or which may be easily and quick y added to a camera previously manufactured. This mechanism is extremely simple in its operation, and acts to hold the pull-down claw used for moving the film out of contact with the film during the reverse movement of the film to prevent injury thereto during the windback operation.

It is a purpose of my invention to provide an additional film winding key which may be operated to rotate the film spools and driving mechanism in a reverse direction, and a finger which may engage the pull-down claw to prevent engagement of this claw with the film during the reverse movement thereof. Thus, by merely operating the finger to disengage the claw from the film, covering the lens opening, and winding the film driving mechanism rearwardly, the film may be rewound upon the supply roll for a second exposure or second partial exposure.

It is a purpose of my invention to provide a windback device which does not affect the operation of any of the working parts of the camera; all of the mechanism of the camera working normally with the exception that the claw is held away from the film. Thus no clutches are required, and all of the elements remain in timed relationship throughout the rewinding operation. Even the lens shutter operates in the usual manner, exposure of the film during the windback operation being prevented by closing the lens opening in some simple manner, as by placing the thumb over the lens barrel.

These and other objects and novel features of my invention will be more clearly and fully set forth in the following specification and claims.

In the drawing forming a part of my specification:

Figure 1 is a side elevation View of a portion of the outer housing or casing of a camera embodying my windback device.

Figure 2 is a side elevation view of the camera with one side removed showing the gearing con necting the power drive of a typical camera to the pull-down mechanism and shutter, showing my windback device attached thereto.

Figure 3 is a perspective view of a fragmentary detail showing the pull-down claw, its connection with its supporting arm, and the claw release mechanism for holding the claw out of engagement with the film.

Figure 4 is a perspective view of the mechanism illustrated in Figure 3, the view being taken from the opposite side of the mechanism.

Figure 5 is a side elevation view of the mechanism illustrated in Figure 3, the View being taken from the same position as Figure 2, and showing the claw release in inoperative position, the operative position being indicated by dotted outline.

Figure 6 is a side elevation detail View of the film moving claw mechanism.

My windback device is shown applied to a camera such as that shown in Patent 2,011,342, issued August 13, 1935, to Joseph Mihalyi. t should be understood that my device can be added to other forms of cameras, most of the structure of the camera not being important to the pres nt in- 39. This slot may be shaped to provide a nonvention. uniform movement of the lever, and to move the The camera illustrated embodies a housing it claw d6 downwardly more quickly than it moves which may be provided with ahandle ii connectupwardly, and so that the film remains staed to the housing by links 52. The links it may tionary for a greater length of time. form spaced finders for the camera. The hous- The movement of the film shutter is coordinated ing It includes a front wall it, upon which is with the movement of the film. A stud 55 is mounted the usual type of objective mounted in a mounted on the lever 39. A lever 51 is pivoted on lens barrel Id. The side l5 of the housing supthe stud 56; and has an arm 59 terminating in ports a spring motor winding key it, and the mo- 10 a pivot Gil to which there is attached a slidable tor release button ll extends through this side rod ti. The rod ti is mounted to slide freely in wall i5 so that the motor may be released to a bearing 52 at its upper end and the lever 5'! move the film past the lens opening. is provided with a cam slot 63 by which the lever As best seen in Figure 2 of the drawing, the is oscillated to operate the shutter plate 64 which winding key it is secured to the shaft i8 which, is attached to the rod 6! and which may move when rotated, winds a spring motor 2%. A freely through a slot 65 in the mechanism plate ratchet wheel 2! and a pawl 22 are employed to 34. retain the spring motor against rearward The slot 63 in the lever 57 is a straight slot and movement during winding. A gear 23 is secured it engages the eccentric stud 29 which also moves to the spring motor 29 for rotation thereby, this 20 the cam operating the pull-down mechanism.

E b i tu e by the spr ng of the motor 26. Thus the shuter operating lever 51 is pivoted to A pinion 24 is in mesh with the gear 23, and acts the pull-down carrying lever and is operated by to rotate a shaft 25 bearing the large gear 25. the same eccentric stud. This makes is unneces- The gear 25 n n e he W h a pin on 2? carsary to adjust the shutter to operate in timed reryihg n eccentric st d 9. oncentric film g5 lation with the claw 4t. Pivoting the lever 51 driving drum 23 s aisc driven y e Spring to the lever 39 has the elfect of uncovering the motor 28. exposure during the time the film remains sta- An eccentric lug 3!! is mounted on the pinion tionary, 21; and is engageable with a latch member at I provide a slide 66 attached to the bridge mounted on a slide 32. The slide 32 is slidably 3O br ck t 33 by screws or rivet 67 which engage mounted p a bridge a ket on the m in slots 69 in the slid to. A spring it holds the anism plate 34 of the camera, which bracket s slide 66 normally at one extremity of its move- Secured y Screws 35 t0 e plate e Slide ment, and is attached to one end of the slide 66 32 s p d with an op i which s e and to the bridge bracket 33. The other end gaged b a p extending inwardly from the 35 of the slide 66 is provided with a transversely ex- Piish button i7. y Sliding e release button tending arm H which extends through the mechl'! downwardly in the direction of the arrow in anism plate 34 and is previded with an upwardly Fi ur 1. h s i 3 i mov d d wnwa y. m vextending end 72, as best seen in Figures 3, 4 and ing the latch member 3! out of engagement with 6 of th drawing, the eccentric lug 3%. When the latch 3i is diS- 40 A top pin 13 projects laterally from the claw en a d from the lu 39, th sp g m t r i Wil it. This pin 13 is normally spaced forwardly drive the mechanis TO p the a a. the from the upwardly extending end 72 of the claw push button I! is released, the spring ii? slidi ib. However, when the slide 65 is moved forh S i e 32 p y d a OWing the latch 3i wardly, against the tension of the spring lil, this to engage the eccentric lug 36. end '52 engages the pin 13 on the claw as and The shutter mechanism consists in an L- pivots the claw about its pivot 45, flexing the shaped lever 39 which is pivoted at it to the spring 5!. As long as the slide 65 is in its forward mechanism plate 35. An end l! of the lever 39 osition, the end 72 engages the pin 13 and holds is slotted at 4-2 so that it may slide freely upon p the claw out of engagement with the film. The a pin 43. The pivot point 4 is substa y Gil claw will be reciprocated or oscillated by the the radius of the lens aperture. It may thus be lever 39, but will remain out of contact with the seen that the end 4! of the lever 39 which slides film, and thus will not prevent the film from about the pin 4-3 follows the curve of the film being wound in a reverse direction. gate. This end ll carries a portion Gd which is In order to operate the slide 65, I provide an bent to ass through the mechanism p ate operating button M which is secured to the slide and this portion M carries a stud 5 on which 66 and which extends through the side wall l5 the pull-down mechanism or claw is mounted, of the housing It. The button I i extends as designated by the numeral M. The claw through a slot in the wall l5; and by pressing the carries a lug t! adapted to strike the abutment button i i forwardly, the slide 56 may be moved d9 to limit its movement toward the film 5t 60 forwardly to bring the upwardly projecting end und r the im ls of t sp he sp in 72 of the same into engagement with the pin 13 50 lways t n s t hold the law it in nsaeeon the claw at, disengaging the claw from the ment with the film. The claw 66 is wider than film 59,

the width of the film apertures 52, so that the In order to rotate the film in a reverse direcclaw cannot pass through the aperture, the end tion, I drill and tap a hole in the shaft 25. Into of the claw always engaging one side of the film. this tapped hole, I thread a square shank '55 In the downward movement of the claw, this which projects through the wall E5 of the housclaw end 53 engages the lower edge Ed of the film ing iii. A key or crank it may be engaged upon apertures 52, moving the film 5i! downwardly as the shank 15 by means of which the shaft 25, the lever 39 is moved. During the upward move- 70 and the rest of the associated mechanism, may ment of the lever 39 the claw moves against the be operated. Thus the film spools, indicated by action of the spring 5! and rides over the back the numerals 82 and 83, and the film driving surface of the film 59. drum 28 may be operated in a reverse direction.

The lever 39 is oscillated by the eccentric stud One of the film spools is mounted on the shaft 29 which passes through a slot 55 in the lever 15 ll bearing the pulley ill. The pulley 79 is opererative pos ardly extending end forms a decorative bearing plate name plate through w oh the shank l extends.

In accordance with the patent statutes, I have described the principles of construction and operation of windback device, and while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that obvious changes may be within the scope of the iollo .g claims without departing from the spirit of my invention.

I claim:

1. A windback device for motion picture apparatus comprising a pa of film spools, a constantly operable film driving means en aging the film between said film spools, a pull-down claw engaging the apertures in the film to more the same downwardly, a spring urging said claw into engagement with said film, means engaging said claw to hold said claw out of engagement with said film, and auxi iary means for moving said film upwardly in a reverse direction while said claw is out of en agement with said film.

2. A windbacla device for motion picture apparatus comprising a pair or" spools, a constantly operable film driving means operable in a, forward direction only engaging the film at spaced points between said spools, a pull-down claw engaging said film between said spaced points, spring means holding said pull-down claw in engagement with said film, means engageable with said pull-down claw to hold said claw out of contact with the film, and auxiliary means engaging said film driving means for moving said film in a reverse direction while said claw is out of contact with the film.

3. A windback device for motion picture apparatus comprising a pair of film spools, a constantly operable film driving means operable in a forward direction on y engaging the film at spaced points between said spools, a pull-down claw engaging the film between said spaced points, means connecting said driving means and said pull-down claw to reciprocate the claw during operation of the film driving means, means engaging said claw to hold the same out of engagement with the film during reciprocation thereof, and auxiliary means engaging said film driving means to move the film in a reverse direction while said claw is out of engagement with the film.

4. In combination with a camera having an objective and means for guiding a film past said objective, a claw for engaging the film to move the same in one direction, an oscillating lever supporting the claw to oscillate the same, and a spring urging the claw into engagement with the film; a Slidably supported means movable between an operative and an inoperative position, said slidably supported means operable in operative position to engage said claw and hold the same out of engagement with the film during oscillation thereof and independently operable means for moving said film in either direction.

5. In combination with a camera having an objective and means for guiding a film past said objective, a claw for engaging the film to move the same in one direction, an oscillating lever supporting the claw to oscillate the same, and a spring urging the claw into engagement with the film; a slidably supported means movable between an operative position and an inoperative position, said slidably supported means operable in operative position to engage said claw and hold the same out of engagement with the film, and means for moving the film in a reverse direction.

6. In combination with a camera having an objective and means for guiding a film past said objective, a claw for engaging the film to move the same in one direction, an oscillating lever supporting said claw to oscillate the same, and a spring urging said claw into engagement with the film; a means continuously engageable with said claw during oscillation thereof to hold said claw out of engagement with said film throughout the longitudinal movement of said claw, and means for moving the film in the opposite direction.

7. In combination with a camera having an objective and means for guiding a film past said objective, a claw for engaging the film to move the same in one direction, means for moving said claw longitudinally of said film, and a spring urging said claw into engagement with said film; a means engageable with said claw during longitudinal movement thereof to hold said claw out of engagement with said film throughout the longitudinal movement of said claw, and means for moving said film in the opposite direction.

8. A windback device for motion picture apparatus comprising a pair of film spools, a film extending therebetween, a claw engaging said film, means reciprocating said claw to move the film in one direction, means engageable with said claw during reciprocation thereof to hold the claw out of engagement with the film during this reciprocation, and auxiliary means engaging said film for moving said film in a reverse direction while said claw is out of contact with the film.

9. In a motion picture having an objective, a pull-down mechanism for the film including a film engaging claw and an oscillating lever carrying said claw, a normally inoperative means engageable with the claw, said normally inoperative means holding said claw constantly out of engagement with the film during oscillation of said lever, and auxiliary means engaging said film for moving said film in a reverse direction While said claw is out of contact with the film.

10. In combination with a camera having an objective and means for guiding a film past said objective, 9. claw for engaging the film to move the same in one direction, an oscillating lever supporting said claw to oscillate the claw, and a spring urging the claw into engagement with the film; a means engageable with the claw during oscillation thereof to hold the claw constantly out of engagement with the film, and auxiliary means engaging said film for moving said film in a reverse direction while said claw is out of contact with the film.

LACEY L. HARMON. 

